C270 Scraping Noise

[Dex]

Hi Folks

05 Plate, Avantegarde Estate.

I have a scraping noise that is perfectly proportional to speed with regard to it's frequency.

At first I thought it was in the centre console, so stripped that, radio, vents, climate all removed, noise still apparent.

No loose cables or plastic bits on the inside.

I have searched here as I remember a recent thread that mentioned the parking brake cable clips failing causing the cable to contact the prop shaft, sounded feasible, but no, it's clipped.

Today I noticed that when turning left it clears (this also sounds familiar, but can't find the thread) it also clears a little when the parking brake is pressed slightly.

Could this noise be the bearing on the gearbox output shaft? looking earlier I could feel a very slight side to side movement of the prop shaft at the gearbox end.

There are a lot of covers underneath, I was struggling to figure how to remove them, no screws or nuts in sight, just upside down 'T' shaped fastenings with a kind of thread, not to dissimilar to trim fixings, but without the 'prettyness'

Any thoughts welcome, the car does have a 'Black Horse aftermarket warranty' but think it is better to get a diagnosis before calling them.

Cheers

Derek

 

[television]

I think what I would do is, jack one rear wheel and place a axle stand under the trolley jack lifting point and start the car up and put it in gear, the raised back wheel will spin, and see if you can hear it, then try the other side.
I do not think that it is in the box

 

[Dex]

I thought of doing that Malcolm, but am worried that the traction control will do it's thing and send the car into the neighbors house!

Derek

 

[television]

I thought of doing that Malcolm, but am worried that the traction control will do it's thing and send the car into the neighbors house!

Derek

Then if you have 2 axle stands place on each side

 

[Dex]

Then if you have 2 axle stands place on each side

Bejesus that scares me too, but you have a point!

 

[television]

Have you tried coasting in N to see if the noise is there, try and pin point the noise by having a passenger in the rear that can open the windows

 

[whitenemesis]

Does it disappear if you apply the brakes?

 

[Dex]

The noise is still there in N, still there with the main brakes but seems to reduce some under acceleration..... of course the last may just be because the car is being noisier :Oops:

Describing is difficult, scraping / ticking....... but slow at slow speeds, increasing with speed, is definitely from the tunnel area. I have tried driving in built up areas with the windows down, but can't hear it outside.

The selector lever linkage is loose underneath the car, but I'm certain that is not the cause, it is not rubbing on anything. Disappearing when turning left really foxes me.

 

[type49]

Do not fear The problem is likely to be the handbrake cable has a broken clip & hanging down, touching the prop. Very difficult to see without putting car on a ramp & removing the heat shield between exhaust & prop. Look for the blue clips. I would buy a new clip from Mercs (about £1) beforehand & then try to get the car up in the air (maybe friendly tyre/exhaust place), so you are then all ready to fit new part.

 

[Dex]

Do not fear The problem is likely to be the handbrake cable has a broken clip & hanging down, touching the prop. Very difficult to see without putting car on a ramp & removing the heat shield between exhaust & prop. Look for the blue clips. I would buy a new clip from Mercs (about £1) beforehand & then try to get the car up in the air (maybe friendly tyre/exhaust place), so you are then all ready to fit new part.

I'm not sure how to remove the heat shield though! The hand brake clips are all in place (as far as I can see without removing the shield) will have to take another look!

Thanks for the thoughts folks.

Derek

 

[type49]

I'm not sure how to remove the heat shield though! The hand brake clips are all in place (as far as I can see without removing the shield) will have to take another look!

Thanks for the thoughts folks.

Derek

You will not see it without removing the thin tin/alloy shield just behind the gearbox - 4X 8mm nuts. You are looking for blue clips.

 

[mercmadjim]

Peter Sellers once drove around with Spike Milligan in his boot, trying to trace a noise, do you have good friend who could do that for you??...........perhaps that is not a good idea.....

 

[Dex]

You will not see it without removing the thin tin/alloy shield just behind the gearbox - 4X 8mm nuts. You are looking for blue clips.

Yay....... just crawled under again, exactly as described Type49, many thanks. I just removed the clip, drilled a hole in it and used a tie wrap, see how long it lasts, but will save a trip to the dealers next week.

What foxed me is that I had no notion it would cross the prop shaft...... but obviously our RHD cars are in the minority!

Thanks again all, but it was close to getting G-A-R-Y climbing in the back as mercmadjim suggested......

Derek